全文获取类型
收费全文 | 92416篇 |
免费 | 1549篇 |
国内免费 | 716篇 |
专业分类
电工技术 | 1155篇 |
综合类 | 2684篇 |
化学工业 | 12970篇 |
金属工艺 | 5200篇 |
机械仪表 | 3427篇 |
建筑科学 | 2761篇 |
矿业工程 | 720篇 |
能源动力 | 1399篇 |
轻工业 | 4101篇 |
水利工程 | 1380篇 |
石油天然气 | 628篇 |
武器工业 | 34篇 |
无线电 | 10655篇 |
一般工业技术 | 17499篇 |
冶金工业 | 3322篇 |
原子能技术 | 332篇 |
自动化技术 | 26414篇 |
出版年
2023年 | 124篇 |
2022年 | 228篇 |
2021年 | 315篇 |
2020年 | 196篇 |
2019年 | 199篇 |
2018年 | 14659篇 |
2017年 | 13587篇 |
2016年 | 10176篇 |
2015年 | 852篇 |
2014年 | 604篇 |
2013年 | 733篇 |
2012年 | 3610篇 |
2011年 | 9974篇 |
2010年 | 8789篇 |
2009年 | 6026篇 |
2008年 | 7309篇 |
2007年 | 8198篇 |
2006年 | 572篇 |
2005年 | 1534篇 |
2004年 | 1415篇 |
2003年 | 1465篇 |
2002年 | 801篇 |
2001年 | 322篇 |
2000年 | 388篇 |
1999年 | 280篇 |
1998年 | 338篇 |
1997年 | 244篇 |
1996年 | 253篇 |
1995年 | 165篇 |
1994年 | 143篇 |
1993年 | 106篇 |
1992年 | 75篇 |
1991年 | 74篇 |
1990年 | 42篇 |
1989年 | 40篇 |
1988年 | 41篇 |
1987年 | 28篇 |
1969年 | 25篇 |
1968年 | 43篇 |
1967年 | 34篇 |
1966年 | 42篇 |
1965年 | 44篇 |
1963年 | 28篇 |
1960年 | 30篇 |
1959年 | 35篇 |
1958年 | 37篇 |
1957年 | 36篇 |
1956年 | 34篇 |
1955年 | 63篇 |
1954年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Somsak Vanit-Anunchai Jonathan Billington Guy Edward Gallasch 《International Journal on Software Tools for Technology Transfer (STTT)》2008,10(1):29-56
State space explosion is a key problem in the analysis of finite state systems. The sweep-line method is a state exploration
method which uses a notion of progress to allow states to be deleted from memory when they are no longer required. This reduces
the peak number of states that need to be stored, while still exploring the full state space. The technique shows promise
but has never achieved reductions greater than about a factor of 10 in the number of states stored in memory for industrially
relevant examples. This paper discusses sweep-line analysis of the connection management procedures of a new Internet standard,
the Datagram Congestion Control Protocol (DCCP). As the intuitive approaches to sweep-line analysis are not effective, we
introduce new variables to track progress. This creates further state explosion. However, when used with the sweep-line, the
peak number of states is reduced by over two orders of magnitude compared with the original. Importantly, this allows DCCP
to be analysed for larger parameter values.
Somsak Vanit-Anunchai was partially supported by an Australian Research Council Discovery Grant (DP0559927) and Suranaree
University of Technology.
Guy Edward Gallasch was supported by an Australian Research Council Discovery Grant (DP0559927). 相似文献
32.
Takeshi Shiofuku Norihiro Abe Yoshihiro Tabuchi Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2008,13(1):290-293
This paper presents an approach of measuring in real-time the vector of finger that is pointing to an object. DSP is used
in the operation processing unit in order to do the real-time processing. The steps include the extraction of flesh-colored
regions from an image, the labeling of the flesh-colored regions, and the detection of two characteristic positions on the
finger so that the direction that the finger is pointing at will be calculated. The entire process takes about 29 msec, which
makes it possible to have the frame rate of 34 fps. With this frame rate, this measurement approach is considered real-time
and promising to be merged into other application systems.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
33.
34.
35.
36.
37.
ETRⅠ-30调速器是瑞士爱舍维斯工厂生产的具有PID调节规律的电液调速器。本文对其液压控制系统作了较详细的介绍,供有关人员参考。 相似文献
38.
This paper presents an artificial intelligence approach of using evolutionary programming to estimate the transient and subtransient parameters of a generator under normal operation. The estimation using evolutionary programming is compared with that using a corrected extended Kalman filter. The comparisons with both simulation and micromachine test results show that evolutionary programming is robust to search the real values of parameters even when the data are highly contaminated by noise, while with the extended Kalman filter, the estimation tends to diverge with such data 相似文献
39.
In this study, an aluminum based metallic matrix (Al-2wt.% Cu) was reinforced with SiC particulates using a conventional casting technique and a new disintegrated melt deposition technique. Microstructural characterization studies conducted on the samples taken from disintegrated melt deposition technique revealed a more uniform distribution of SiC particulates and good interfacial integrity between SiC particulates and metallic matrix when compared to the conventionally cast composite samples. Results of ambient temperature mechanical tests demonstrate an increase in 0.2% YS and ultimate tensile strength of samples taken from disintegrated melt deposition technique when compared with the unreinforced and conventionally cast composite samples. The results of microstructural characterization and mechanical testing were finally rationalized in terms of the nature of processing technique employed to reinforce Al-2wt.% Cu metallic matrix with SiC particulates. 相似文献
40.